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Abstract:

A sprinkler head A has a main body including a pipe connection portion
and a frame portion. In the frame portion, an outer circumferential
surface protruding to the outside of the pipe connection portion is
provided, and beam-like portions (inward flanges) with which a lever of a
thermo-sensitive breakup portion engages and openings obtained by cutting
off the outer circumferential surface from the side of the pipe
connection portion to the beam-like portion are provided at opposite
positions in the outer circumferential surface. Thereby, the weight of
the frame portion can be largely reduced. Therefore, the weight of a
sprinkler head is reduced, so that the weight load applied to the fire
extinguishing system pipes in which a large number of sprinkler heads are
installed can be reduced, and the work burden due to the weight load when
the sprinkler heads are conveyed and installed in the fire extinguishing
system pipes can also be reduced.

Claims:

1. A sprinkler head characterized by comprising: a pipe connection
portion, one end of which is connected to a fire extinguishing system
pipe and the other end of which has a water outlet; a cylindrical frame
portion, one end of which is connected to the water outlet and the other
end of which has an opening end; and a thereto-sensitive breakup portion
which holds a pressing force of a valve body closing the water outlet and
has a lever to which a reaction force of the pressing force is applied,
wherein the frame portion has an outer circumferential surface protruding
outside of the pipe connection portion, and the frame portion has
beam-like portions with which the lever is engaged and opening portions
obtained by cutting off the outer circumferential surface from the side
of the pipe connection portion to the beam-like portion at opposite
positions in the outer circumferential surface.

2. The sprinkler head according to claim 1, wherein the opening portion
is provided at an inner position nearer to a central axis of the frame
portion than an outer circumferential surface of the beam-like portion.

3. The sprinkler head according to claim 1, wherein the pipe connection
portion and the frame portion are a forged body having an integrated
structure.

4. The sprinkler head according to claim 1, wherein the thermo-sensitive
breakup portion is a unit component in which a plurality of components
are combined.

5. The sprinkler head according to claim 1, wherein a lever engaging
portion engaged with the lever of the thermo-sensitive breakup portion is
provided on an inner circumferential surface of the beam-like portion.

6. The sprinkler head according to claim 1, wherein a lever insertion
groove that causes the lever of the thereto-sensitive breakup portion to
be inserted in the frame portion is provided on an inner circumferential
surface of the frame portion.

7. The sprinkler head according to claim 1, wherein a deflector is
provided outside of the opening end of the frame portion.

8. The sprinkler head according to claim 1, wherein a deflector engaging
portion that holds a deflector is provided on the outer circumferential
surface of the frame portion.

9. The sprinkler head according to claim 1, further comprising: a guide
pin, one end of which is provided with a deflector and the other end of
which is engaged with a deflector engaging portion provided on the frame
portion.

10. The sprinkler head according to claim 8, wherein the deflector
engaging portion is provided on the outer circumferential surface of the
frame portion in an outward position of a lever insertion groove.

11. The sprinkler head according to claim 8, wherein the deflector
engaging portion is provided nearer the opening end of the frame portion
than the lever engaging portion.

12. The sprinkler head according to claim 1, further comprising: a load
generation member which is placed between the valve body and the
thermo-sensitive breakup portion, urges the valve body and the lever of
the thermo-sensitive breakup portion engaged with the beam-like portion
in opposite directions from each other, and generates a press load for
the valve body to block the water outlet.

13. The sprinkler head according to claim 12, further comprising: as the
load generation member, a saddle which includes a compression screw
pressing the valve body to the water outlet and a female screw that can
be screwed with the compression screw, urges the thermo-sensitive breakup
portion in a direction opposite to the pressing direction of the valve
body to the water outlet by screwing the compression screw with the
female screw, and engages the lever of the thermo-sensitive breakup
portion with the beam-like portion in a pressing state.

14. The sprinkler head according to claim 13, wherein a through-hole is
provided in the thermo-sensitive breakup portion and an amount of
screwing of the compression screw with the female screw of the saddle can
be adjusted by a tool inserted into the through-hole.

15. The sprinkler head according to claim 1, wherein a support cup having
a cylindrical shape and a bottom portion, which accommodates the frame
portion, is provided in a main body including the pipe connection portion
and the frame portion.

16. The sprinkler head according to claim 15, wherein the main body and
the support cup are connected to each other by a polygonal connection
portion.

17. The sprinkler head according to claim 1, further comprising: a cover
plate that covers over the sprinkler head installed in an opening in a
ceiling so that the sprinkler head is not exposed to the outside and a
cylindrical retainer that holds the cover plate as well as the support
cup.

18. The sprinkler head according to claim 1, further comprising: a
ceiling plate that covers over a boundary between an outer
circumferential surface of the sprinkler head installed in an opening in
a ceiling and an edge of the opening and a cylindrical retainer that
holds the ceiling plate as well as the support cup.

19. The sprinkler head according to claim 1, further comprising: a
cross-sectional U-shaped arm including an attaching portion for the outer
circumferential surface of the frame portion at the upper end thereof and
a deflector at the lower end thereof.

Description:

[0002] A sprinkler head is installed on a ceiling surface or a wall
surface in a building and provided with a nozzle that can be coupled to a
pipe connected to a water source at one end and a thermo-sensitive
actuator at the other end. In a normal condition, the thermo-sensitive
actuator supports a valve body that closes the nozzle.

[0003] As a conventional sprinkler head, a sprinkler head of FIG. 12 is
known (PTL 1). The sprinkler head 50 has a structure in which a pipe
connection portion 51 and a frame 52 are screwed together by a screw 51A.
When the pipe connection portion 51 and the frame 52 are screwed
together, a lever 55 engaged with an inward flange 52A located at the
lower end of the frame 52 and a saddle S are displaced toward the pipe
connection portion 51 and a valve body 54 pressed by the displaced saddle
S is closely attached to a nozzle end 53, so that the nozzle end 53 is
blocked.

[0004] A slit-shaped opening 52B is formed over the inward flange 52A with
which the lever 55 engage. The opening 52B is formed, so that a beam-like
portion 52C is formed in the frame 52 under the opening 52B, and the
inward flange 52A including a step portion is formed on an inner
circumference of the beam-like portion 52C. The lever 55 is engaged with
the inward flange 52A, so that, when a load is added to the beam-like
portion 52C in a position opposite to the opening 52B (downward direction
in FIG. 12), a deflection occurs and resilience is obtained. In other
words, when the pipe connection portion 51 and the frame 52 are screwed
together, a deflection occurs in the beam-like portion 52C by the lever
55 disposed under the opening 52B, and the deflection causes a spring
force. The spring force has a function to explosively eject components of
a thermo-sensitive breakup portion 57 to the outside of the sprinkler
head 50 when the sprinkler head is actuated, so the spring force is
useful for preventing a lodgment (clog of components of the
thermo-sensitive breakup portion 57 when a breakup occurs).

[0007] In the sprinkler head 50 as described above, the pipe connection
portion 51 and the frame 52 are forged parts and heavy, so that it is
required to reduce the weight thereof. In fire extinguishing system pipes
laid down over a ceiling or the like, generally, many sprinkler heads 50
are installed. Therefore, if the sprinkler head 50 is heavy, the weight
of the entire fire extinguishing system becomes heavy, so that many
support metal fittings are required to be used to support the weight.
Thus there is a problem that the entire system cost increases. Although a
metal pipe has been mainly used as a fire extinguishing system pipe, in
recent years, a resin pipe, which is inexpensive and light weight and has
a good constructability by a header construction method (see Japanese
Unexamined Patent Application Publication No. 10-52512 as an example of
the method), is also used instead of the metal pipe. Therefore, to reduce
the weight load applied to the resin pipe as much as possible for a long
period of time, it is desired that the sprinkler head 50 connected to the
resin pipe is further lightened.

[0008] The present invention is made in view of the conventional technique
as described above. The object of the present invention is to lighten the
sprinkler head.

Means for Solving the Problem

[0009] In order to solve the above problem, the present invention provides
a sprinkler head described below.

[0010] The present invention provides a sprinkler head characterized by
including a pipe connection portion, one end of which is connected to a
fire extinguishing system pipe and the other end of which has a water
outlet, a cylindrical frame portion, one end of which is connected to the
water outlet and the other end of which has an opening end, and a
thermo-sensitive breakup portion which holds a pressing force of a valve
body closing the water outlet and has a lever to which a reaction force
of the pressing force is applied. The frame portion has an outer
circumferential surface protruding outside of the pipe connection
portion, and the frame portion has beam-like portions with which the
lever is engaged and opening portions obtained by cutting off the outer
circumferential surface from the side of the pipe connection portion to
the beam-like portion at opposite positions in the outer circumferential
surface.

[0011] The frame portion of the present invention has the outer
circumferential surface protruding outside of the pipe connection portion
and includes the beam-like portions with which the lever is engaged and
the opening portions obtained by cutting off the outer circumferential
surface from the side of the pipe connection portion to the beam-like
portion at opposite positions in the outer circumferential surface.
Thereby, in the present invention, the weight of the frame portion can be
largely reduced. Therefore, the load applied to the fire extinguishing
system pipe can be reduced, and the work burden due to the weight load
when the sprinkler heads are conveyed and installed in the fire
extinguishing system pipes can also be reduced.

[0012] The beam-like portions are located at opposite positions, so the
press load of the lever of thermo-sensitive breakup portion can be
equally applied to each beam-like portion and spring forces caused by
deflection of each beam-like portion can be equally generated. Therefore,
the thermo-sensitive breakup portion can be continuously and stably
maintained over a number of years. The equal spring forces caused by
deflection of each beam-like portion can explosively eject the components
of the thermo-sensitive breakup portion in the axis direction of the
frame portion when the thermo-sensitive breakup portion 4 is activated to
break up, so that the equal spring forces can function to prevent the
lodgment from occurring. Two or more pairs of beam-like portions and
opening portions may be formed in opposite positions instead of one pair
of those.

[0013] The above-described present invention can be configured so that the
thermo-sensitive breakup portion can be inserted from the opening end of
the frame portion.

[0014] Thereby, the thermo-sensitive breakup portion can be inserted from
the opening end of the frame portion, so that the thermo-sensitive
breakup portion can be easily installed inside the frame portion.

[0015] In this case, if the thermo-sensitive breakup portion is a unit
component, the thermo-sensitive breakup portion can be inserted as a unit
component from the opening end of the frame portion, so that the assembly
operation can be simplified.

[0016] In the above-described present invention, the opening portion can
be provided at an inner position nearer to a central axis of the frame
portion than an outer circumferential surface of the beam-like portion.

[0017] To form the slit-shaped opening 52B in the frame 52 in the
conventional technique, not only a process for cutting the inner
circumferential surface and the outer circumferential surface of the
frame 52, but also a dedicated process including a complex cutting
operation by a large machining center is required. However, if the
opening 52B can be formed without depending on such a dedicated process,
the manufacturing cost can be reduced not only as a single component, but
also as the entire sprinkler head 50.

[0018] Therefore, in the present invention, the opening portion is
provided at an inner position nearer to the central axis of the frame
portion than the outer circumferential surface of the beam-like portion.
Thereby, the opening portion can be formed at the same time when the
inner circumferential surface of the beam-like portion is cut, so that it
is possible to reduce the manufacturing cost for forming the opening
portion and providing the beam-like portion without depending on a
dedicated process for forming the opening portion.

[0019] In the above-described present invention, the pipe connection
portion and the frame portion can be a forged body having an integrated
structure.

[0020] Thereby, the number of components can be reduced compared with a
case in which the pipe connection portion and the frame portion are
separate components. Therefore, the cost can be reduced.

[0021] In the above-described present invention, the thermo-sensitive
breakup portion can be a unit component in which a plurality of
components are combined.

[0022] According to the present invention, it is not necessary to mount
the components of the thermo-sensitive breakup portion one by one, so
that the assembly process can be simplified and the manufacturing cost
can be reduced. The handling of the thermo-sensitive breakup portion
during the assembly operation is also good because the thermo-sensitive
breakup portion is a unit component.

[0023] In the above-described present invention, a lever engaging portion
engaged with the lever of the thermo-sensitive breakup portion can be
provided on the inner circumferential surface of the beam-like portion.

[0024] Thereby, the thermo-sensitive breakup portion can be installed
inside the frame portion. To engage the thermo-sensitive breakup portion
with the lever engaging portion, when using a thermo-sensitive breakup
portion including a link in which two thin plates are connected together
by a low melting point alloy and a pair of levers with which the link is
engaged, the thermo-sensitive breakup portion can be mounted on the lever
engaging portion while one end of the lever is engaged with the lever
engaging portion and the other end is engaged with the link. When the
thermo-sensitive breakup portion is the above-described unit component,
the lever only has to be engaged with the lever engaging portion on the
inner circumferential surface of the frame portion, so that the
thermo-sensitive breakup portion can be easily mounted.

[0025] In the above-described present invention, a lever insertion groove
that causes the lever of the thermo-sensitive breakup portion to be
inserted in the frame portion can be provided on the inner
circumferential surface of the frame portion.

[0026] Thereby, when the thermo-sensitive breakup portion is inserted into
the frame portion, the lever engaging portion does not interfere with the
thermo-sensitive breakup portion, so that the thermo-sensitive breakup
portion can be easily inserted with good operability.

[0027] The thermo-sensitive breakup portion can be configured so that the
thermo-sensitive breakup portion is inserted into the frame portion when
the lever is inserted into the lever insertion groove and the lever is
engaged with the lever engaging portion when the thermo-sensitive breakup
portion is rotated around the axis of the frame portion. Thereby, when
the thermo-sensitive breakup portion is rotated, the lever is engaged
with the lever engaging portion, so that the assembly operation can be
easily performed.

[0028] For example, the lever insertion groove as described above can be
formed at a position rotated about 20° to 90° from the
lever engaging portion.

[0029] In the above-described present invention, a deflector can be
provided outside of the opening end of the frame portion.

[0030] Thereby, a deflector having a shape according to specification and
usage of the sprinkler head can be placed outside the frame portion, so
that many types of sprinkler heads in which the pipe connection portion,
the frame portion, and the thermo-sensitive breakup portion are used in
common can be developed.

[0031] In the above-described present invention, a deflector engaging
portion that holds a deflector can be provided on the outer
circumferential surface of the frame portion.

[0032] Thereby, a deflector having a shape according to specification and
usage of the sprinkler head can be placed outside the frame portion, so
that many types of sprinkler heads in which the pipe connection portion,
the frame portion, and the thermo-sensitive breakup portion are used in
common can be developed.

[0033] In the above-described present invention, a guide pin, one end of
which is provided with a deflector and the other end of which is engaged
with a deflector engaging portion provided on the frame portion, can be
provided.

[0034] Thereby, the deflector can be reliably activated by a simple
configuration using a guide pin.

[0035] In the above-described present invention, the deflector engaging
portion can be provided on the outer circumferential surface of the frame
portion in an outward position of the lever insertion groove.

[0036] Thereby, the position of the lever of the thermo-sensitive breakup
portion is separated from the deflector engaging portion, so that the
lodgment can be effectively prevented when the thermo-sensitive breakup
portion is activated to break up. In other words, the lever insertion
groove is located on the inner circumferential surface of the frame
portion at which the deflector engaging portion is provided, so that the
lever of the thermo-sensitive breakup portion cannot be engaged there.
Therefore, the lever is engaged with the lever engaging portion located
away from the deflector engaging portion. Thereby, in the present
invention, it is possible to prevent the lever from hitting the guide pin
when the thermo-sensitive breakup portion is activated to break up and
lever flies and drops when the sprinkler head is activated, so that the
lodgment can be prevented when the thermo-sensitive breakup portion is
activated to break up.

[0037] In the above-described present invention, the deflector engaging
portion can be provided nearer the opening end of the frame portion than
the lever engaging portion.

[0038] Thereby, for example, the sprinkler head can be configured as a
frame yoke type sprinkler head in which the deflector engaging portion is
extended in a water discharge direction of the water outlet and the
deflector is provided at the tip of the extended deflector engaging
portion. In this case, the deflector engaging portion (arm) can be
configured as a part of the frame portion, and also the deflector
engaging portion (arm) can be configured as a member separate from the
frame portion.

[0039] In the case of a concealed type sprinkler head, components other
than a cover plate are arranged over the ceiling, and when a fire occurs,
the deflector slides and protrudes from the lower surface of the ceiling
and then water is sprinkled. To obtain a correct water sprinkling
distribution performance, it is preferred that the deflector is protruded
as much as possible from the lower surface of the ceiling. To increase
the amount of the protrusion, the length of the guide pin that holds the
deflector is increased or the stroke of the guide pin is increased.
However, there is a problem that the manufacturing cost increases.
Therefore, as described in the present invention, as a configuration in
which the deflector engaging portion is provided nearer to the opening
end of the frame portion than the lever engaging portion, the deflector
engage portion is located nearer to the ceiling surface as much as
possible, so that the amount of the protrusion of the deflector from the
ceiling surface can be increased without depending on the lengthening of
the guide pin or the stroke of the guide pin. The amount of the
protrusion of the deflector from the ceiling surface, that is, a range of
movement of the deflector, can be large, so that, even when there is a
construction difference between the connection port of the fire
extinguishing system pipe and the ceiling surface, the difference can be
absorbed if the difference is within the range of movement of the
deflector, and an attachment adjustment range of a concealed type
sprinkler head can be enlarged when the sprinkler head is installed.
Therefore, the installation is easily performed.

[0040] The above-described present invention can include a load generation
member which is placed between the valve body and the thermo-sensitive
breakup portion, urges the valve body and the lever of the
thermo-sensitive breakup portion engaged with the beam-like portion in
opposite directions from each other, and generates a press load for the
valve body to block the water outlet.

[0041] More specifically, the above-described present invention can
include, as the load generation member, a saddle which includes a
compression screw pressing the valve body to the water outlet and a
female screw that can be screwed with the compression screw, urges the
thermo-sensitive breakup portion in a direction opposite to the pressing
direction of the valve body to the water outlet by screwing the
compression screw with the female screw, and engages the lever of the
thermo-sensitive breakup portion with the beam-like portion in a pressing
state.

[0042] Thereby, the valve body and the thermo-sensitive breakup portion
are urged in a separating direction by screwing the compression screw
with the female screw of the saddle, so that a pressing force of the
valve body to the water outlet and a deflective deformation of the
beam-like portion caused by the lever of the thermo-sensitive breakup
portion can be generated. By such a simple component configuration and a
simple assembly operation, a load necessary for water block performance
of the valve body and deflective deformation of the beam-like portion can
be obtained.

[0043] In the above-described present invention, a through-hole is
provided in the thermo-sensitive breakup portion and an amount of
screwing of the compression screw with the female screw of the saddle can
be adjusted by a tool inserted into the through-hole.

[0044] Thereby, the assembly operation is completed by inputting all the
components such as the valve body into the frame portion, and then
adjusting the amount of screwing of the compression screw by a tool
inserted through the through-hole of the thermo-sensitive breakup
portion. Therefore, the assembly operation can be easily performed.

[0045] In the above-described present invention, a support cup having a
cylindrical shape and a bottom portion, which accommodates the frame
portion, can be provided in a main body including the pipe connection
portion and the frame portion.

[0046] Thereby, it is possible to configure a concealed type sprinkler
head that is buried and installed in a ceiling and a flush type sprinkler
head in which the deflector is normally held near a ceiling and the
deflector protrudes from the ceiling and sprinkles water when being
activated.

[0047] The above-described present invention can be configured so that the
main body and the support cup are connected to each other by a polygonal
connection portion.

[0048] Thereby, the main body and the support cup are solidly connected to
each other so that the main body and the support do not cause
simultaneous bolt-nut rotation.

[0049] The above-described present invention can be configured to include
a cover plate that covers over the sprinkler head installed in an opening
in a ceiling so that the sprinkler head is not exposed to the outside and
a cylindrical retainer that holds the cover plate as well as the support
cup.

[0050] Thereby, the present invention can be implemented as a concealed
type sprinkler head which covers over and hides the sprinkler head and
the hole through which the sprinkler head penetrates so as not to spoil
the beauty of the room.

[0051] Further, the above-described present invention can be configured to
include a screwing groove on the outer circumferential surface of the
support cup and an engaging portion which engages with the screwing
groove on the retainer. Thereby, the support cup and the retainer can be
easily connected to each other by screwing.

[0052] The above-described present invention can be configured to include
a ceiling plate that covers over a boundary between an outer
circumferential surface of the sprinkler head installed in an opening in
a ceiling and an edge of the opening and a cylindrical retainer that
holds the ceiling plate as well as the support cup.

[0053] Thereby, the present invention can be implemented as a flush type
sprinkler head with a ceiling plate, which covers over and hides the
sprinkler head and the hole through which the sprinkler head penetrates
so as not to spoil the beauty of the room.

[0054] Further, the above-described present invention can be configured to
include a screwing groove on the outer circumferential surface of the
support cup and an engaging portion which engages with the screwing
groove on the retainer. Thereby, the support cup and the retainer can be
easily connected to each other by screwing.

[0055] The above-described present invention can be configured to include
a cross-sectional U-shaped arm including an attaching portion for the
outer circumferential surface of the frame portion at the upper end
thereof and a deflector at the lower end thereof.

[0056] Thereby, the present invention can be configured as a frame type
sprinkler head.

Advantageous Effects of Invention

[0057] According to the sprinkler head of the present invention, the
sprinkler head can be lightened, so that the weight load applied to the
fire extinguishing system pipes can be reduced. This contributes to
reduction of the weight of the fire extinguishing system pipes, so that
use of the support metal fittings of the pipes can be reduced and the
system cost can be reduced. Further, the aging degradation of the resin
pipes used instead of the metal pipes as the fire extinguishing system
pipes can be suppressed. Furthermore, the work burden due to the weight
load when the sprinkler heads are conveyed and installed in the fire
extinguishing system pipes can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

[0058] FIG. 1 is a cross-sectional view of a sprinkler head according to a
first embodiment.

[0059] FIG. 2 is a front view of the sprinkler head of FIG. 1.

[0060] FIG. 3 is a side view of FIG. 2.

[0061] FIG. 4 is a cross-sectional view of a thermo-sensitive breakup
portion.

[0062] FIG. 5 is an exploded perspective view of the thermo-sensitive
breakup portion.

[0063] FIG. 6 is an exploded cross-sectional view of a cylinder/plunger.

[0064] FIG. 7 is a cross-sectional view of the sprinkler head of FIG. 1
when the sprinkler head is installed.

[0065] FIG. 8 is a cross-sectional view taken along line X-X in FIG. 7.

[0066] FIG. 9 is an enlarged diagram of a portion indicated by Y in FIG.
7.

[0067] FIG. 10 is a cross-sectional view of a sprinkler head according to
a second embodiment.

[0068] FIG. 11 is a cross-sectional view of a sprinkler head according to
a third embodiment.

[0069] FIG. 12 is a cross-sectional view of a sprinkler head according to
a modified example of the embodiments.

[0070] FIG. 13 is a cross-sectional view of a conventional sprinkler head.

BEST MODES FOR CARRYING OUT THE INVENTION

First Embodiment

FIGS. 1 to 9

[0071] Hereinafter, a first embodiment of a sprinkler head of the present
invention will be described with reference to FIGS. 1 to 9.

[0072] A sprinkler head A of the first embodiment includes a main body 1,
a valve body 3, a thermo-sensitive breakup portion 4, a deflector 5, a
support cup 6, and a cover plate 7. The sprinkler head A is configured as
a concealed type sprinkler head.

[0073] The main body 1 shown in FIGS. 1 to 3 has a hollow shape. One end
of the main body 1 is a pipe connection portion 1A on which a male screw
is formed, which can be connected to a pipe filled with water. The other
end of the pipe connection portion 1A is a water outlet 1B. The end of
the water outlet 1B is blocked by the valve body 3.

[0074] A support cup engaging portion 1C, whose outer circumference has a
polygonal cross-sectional shape, is formed between the pipe connection
portion 1A and the water outlet 1B. A flange portion having an outer
circumference larger than that of the support cup engaging portion 1C is
formed on the water outlet side 1B of the support cup engaging portion
1C, and a cylindrical frame portion 2 is formed from the edge of the
flange portion toward a water discharge side. The main body 1 includes
the pipe connection portion 1A and the frame portion 2 having an outer
circumference surface larger than that of the pipe connection portion 1A.

[0075] The horizontal cross-sectional shape of the outer circumference of
the frame portion 2 has a shape obtained by cutting off two portions of a
circle in parallel. Specifically, two straight line segments from which
the two portions are cut off and arc segments between the straight line
segments are formed. Therefore, on the outer circumference surface of the
frame portion 2, curved surface portions 2A having a circular-arc
cross-sectional shape and planar surface portions 2B having a linear
cross-sectional shape are formed. The planar surface portion 2B is formed
as a cut-off surface portion formed by cutting off the outer
circumference of the frame 2 from the side facing the pipe connection
portion 1A to a beam-like portion 2J described later, and an opening 2E
is formed there. The cross-sectional shape of the outer circumference of
a lower portion of the frame 2 is a circle which does not include the
planar surface portions 2B and has the same radius as that of the curved
surface portions 2A. Specifically, the beam-like portions 2J, which are
made of an arc-shaped portion provided along the circumferential
direction of the frame 2, are formed under the planar surface portions
2B. The beam-like portions 2J are formed in opposite positions around the
cylinder axis of the frame portion 2.

[0076] An inward flanges 2C, which are formed to extend inwardly, are
formed on a lower inner circumference of the frame portion 2 (inner
circumference surfaces of lower portions of the curved surface portions
2A and inner circumference surfaces of the beam-like portions 2J). Lever
insertion grooves 2D and 2D are formed on the inward flanges 2C located
at lower portions of the curved surface portions 2A (FIG. 1).

[0077] The opening 2E is formed in the planar surface portion 2B of the
frame portion 2 rotated substantially 90° from the lever insertion
groove 2D. The opening 2E is formed by boring the inside of the frame
portion 2 by a diameter smaller than the outside diameter of the curved
surface portion 2A and larger than the distance between the two planar
surface portions 2B.

[0078] The inward flange 2C of the beam-like portion 2J located under the
opening 2E becomes a lever engaging portion 2F with which a lever 11 of
the thermo-sensitive breakup portion 4 described later engages. The lever
engaging portion 2F is provided on the beam-like portion 2J under the
opening 2E, so that, when a load is applied to the lever engaging portion
2F in a direction from the water outlet 1B to the lower end of the frame
portion 2, the beam-like portion 2J is elastically deformed by the
applied load, and the amount of deformation of the beam-like portion 2J
due to the elastic deformation can be larger than that in a case in which
the opening 2E is not provided. The elastic deformation (deflection) of
the beam-like portion 2J generates a spring force. The spring force has a
function to explosively eject components of the thermo-sensitive breakup
portion 4 to the outside when the sprinkler head A is actuated, and the
spring force functions to prevent a lodgment from occurring.

[0079] A deflector engaging portion 2G, which is formed downward from the
lower end of the frame portion 2, is formed on the outer circumference of
the lever insertion groove 2D. A step portion 2H, which can accommodate
the valve body 3, is formed at the boundary between the frame portion 2
and the water outlet 1B. A movement of the valve body 3 when the valve
body 3 is shifted from the water outlet 1B by vibration or shock is
contained within the step portion 2H by the step portion 2H, so that it
is prevented that the valve body 3 is shifted from the water outlet 1B
and water in the water outlet 1B leaks.

[0080] The valve body 3 has a disk shape. The valve body 3 is accommodated
in the step portion 2H. The valve body 3 is pressed onto an end of the
water outlet 1B by a compression screw 21 and the valve body 3 blocks the
water outlet 1B.

[0081] The thermo-sensitive breakup portion 4 is engaged with the inward
flange 2C (lever engaging portion 2F) formed on the beam-like portion 2J
of the frame portion 2. When a fire occurs, the thermo-sensitive breakup
portion 4 is activated to break up by heat of the fire and releases the
valve body 3. The thermo-sensitive breakup portion 4 includes the lever
11, a support plate 12, a balancer 13, a cylinder 14, a plunger 15, a low
melting point alloy 16, and a set screw 17.

[0082] The thermo-sensitive breakup portion 4 is formed as a unit
component as shown in FIG. 4, and can be stored and transported as a unit
component. When the sprinkler head is assembled, the thermo-sensitive
breakup portion 4 is mounted in the main body 1 as a unit component shown
in FIG. 4.

[0083] The levers 11 are used as a pair. One end of the lever 11 is
engaged with the inward flange 2C and has a shape bending outward.
Protrusions 11A, which are provided symmetrically, are formed at an upper
portion of the lever 11 (FIG. 5), and a rectangular hole 11B is made in a
lower portion of the lever 11. The support plate 12 and the balancer 13
are engaged between the pair of levers 11. The support plate 12 is
engaged with the protrusions 11A and the balancer 13 is engaged with the
lower holes 11B. A hole 13A is made in the center portion of the balancer
13, and the cylinder 14 is inserted into the hole 13A.

[0084] The cylinder 14 has a cylindrical shape. A step is formed inside
the cylinder 14. A large diameter portion 14A and a small diameter
portion 14B are formed in the cylinder 14. A circular ring-shaped low
melting point alloy 16 is accommodated in the large diameter portion 14A.
A flange portion 14C is formed on an end of the large diameter portion
14A and the flange portion 14C is engaged with the hole 13A of the
balancer 13. The inside diameter of the small diameter portion 14B is
substantially the same as the inside diameter of the ring-shaped low
melting point alloy 16.

[0085] An end of the small diameter portion 14B is bent so that heat
collectors 18 and 19 are sandwiched by the small diameter portion 14B and
the heat collectors 18 and 19 are provided to the cylinder 14. The heat
collectors 18 and 19 are formed of metal such as copper or copper alloy
with good heat conductivity and have a function to absorb heat caused by
a fire and transfer the heat to the low melting point alloy 16 in the
cylinder 14.

[0086] A large diameter portion 15A and a small diameter portion 15B are
formed on the outer circumference of the plunger 15 by a step. The
outside diameter of the large diameter portion 15 is formed slightly
smaller than the inside diameter of the large diameter portion 14A of the
cylinder 14. The outside diameter of the small diameter portion 15B is
formed slightly smaller than the inside diameter of the small diameter
portion of the cylinder 14 and the inside diameter of the low melting
point alloy 16.

[0087] The plunger 15 is inserted from the large diameter portion 14A of
the cylinder 14, and the small diameter portion 15B and a step portion
15C between the large diameter portion 15A and the small diameter portion
15B come into contact with the low melting point alloy 16. When the
plunger 15 is inserted into the cylinder 14, the outer circumference
surface of the plunger 15 is slidable on the inner circumference surfaces
of the cylinder 14B and the low melting point alloy 16.

[0088] A through-hole 15D is made in the plunger 15 and a step portion 15E
with which the tip of the set screw 17 comes into contact is formed at
the middle of the through-hole 15D.

[0089] The set screw 17 has a cylindrical shape and a male screw 17A is
formed on the outer circumference of the set screw 17. When the male
screw 17A is threaded into a female screw 12A of the support plate 12,
the tip of the set screw 17 presses the step portion 15E of the plunger
15, so that a compression force is applied to the low melting point alloy
16 by the step portion 15E of the plunger 15 and a bottom portion 14D of
the cylinder 14.

[0090] Further, a force is applied to the support plate 12 and the
balancer 13 which are engaged with the pair of levers 11 in a direction
for strengthening engagement with the levers 11, and the engagement state
of the levers 11, the support plate 12, and the balancer 13 is
maintained. Thereby, the thermo-sensitive breakup portion 4 is formed as
a unit.

[0091] A saddle 20 is placed between the thermo-sensitive breakup portion
4 and valve body 3. The saddle 20 is formed of a metal plate member.
Concave portions 20A with which the pair of levers 11 engage are formed
on a surface of the saddle 20. A female screw 20B is formed between the
concave portions 20A and 20A, and the compression screw 21 is threaded
into the female screw 20B. The compression screw 21 and the saddle 20
form a load generation member of the present invention.

[0092] When the compression screw 21 is threaded into the female screw 20B
from the thermo-sensitive breakup portion 4 to the valve body 3, the tip
of the compression screw 21 presses the valve body 3. Thereby, the valve
body 3 is pressed to the end of the water outlet 1B and the valve body 3
blocks the water outlet 1B. At the same time, the pair of levers 11
downwardly press the inward flange 2C of the frame portion 2 with which
the pair of levers 11 are engaged. Thereby, the beam-like portion 2J is
elastically deformed and a slight displacement is generated. By the
displacement caused by the deformation of the beam-like portion 2J, a
spring force to explosively eject the components of the thermo-sensitive
breakup portion 4 to the outside of the frame portion 2 is generated when
the breakup action occurs. In the present embodiment, by a simple
component configuration and a simple assembly operation of the
compression screw 21 and the saddle 20, a load necessary for water block
performance of the valve body 3 and deflective deformation of the
beam-like portion 2J can be obtained.

[0093] The deflector 5 has a flat plate shape, and a plurality of slits 5A
are formed around the deflector 5. Holes 5B and 5B, into which a guide
pin 5C is fitted, are made in the deflector 5. One end of the guide pin
5C is inserted into the hole 5B and fixed by caulking. The guide pin 5C
is inserted into a hole 5E made in the deflector engaging portion 2G of
the main body 1. The guide pin 5C is slidable when the guide pin 5C is
inserted into the hole 5E. A flange portion 5D is formed at the other end
of the guide pin 5C, and the flange portion 5D can be engaged with the
end surface of the of the hole 5E of the deflector engaging portion 2G of
the main body 1.

[0094] The support cup 6 is a cylindrical member with a bottom portion,
which covers the outside of the frame portion 2 of the main body 1. An
opening 6B, into which the support cup engaging portion 1C of the main
body 1 can be fitted, is formed in a bottom portion 6A of the support cup
6. The support cup engaging portion 1C is fitted into and the opening 6B,
so that the support cup 9 is prevented from rotating with respect to the
main body 1.

[0095] A cylindrical portion 6C, which is set upright to the outside, is
formed on the circumferential portion of the opening 6B. The position of
the end surface of the cylindrical portion 6C is nearer to the pipe
connection portion 1A than the end surface of the support cup engaging
portion 1C, and the end of the cylindrical portion 6C is located near a
constricted portion 1D between the pipe connection portion 1A of the main
body 1 and the support cup engaging portion 1C. A cut is made into a
plurality of portions of the bottom of the cylindrical portion 6C, and
then the upper portions of the cuts are pressed in a direction from the
outer circumference to the constricted portion 1D, and the upper portions
of the cuts are deformed toward the constricted portion 1D to form
engaging portions 6D, so that the engaging portions 6D are engaged with
the constricted portion 1D. Thereby, the support cup 6 can be fixed to
the main body 1.

[0096] Base plates 6E, in which the same opening as the opening 6B is
formed, are placed on the inner surface of the bottom of the support cup
6. A plurality of openings 6F are made at regular intervals near the
outer circumference of the bottom surface 6A of the support cup 6. The
opening 6F reaches from the bottom surface 6A to the side surface 6G of
the support cup. A spiral groove 6H is formed on a portion of the side
surface 6G near the end surface.

[0097] The cover plate 7 includes a cover 7A having a thin plate shape
which covers over the main body 1, the thermo-sensitive breakup portion
4, and the deflector 5 in the support cup 6 and a retainer 7B having a
cylindrical shape. The cover plate 7 is connected to the support cup 6
after the pipe connection portion 1A of the main body 1 is connected to a
fire extinguishing system pipe, so that the cover plate 7 is assembled as
a separate component from the main body 1 and the support cup 6.

[0098] The cover 7A has a disk shape and is made of a material such as
copper and copper alloy that easily transfer heat. The retainer 7B has a
cylindrical shape. The tip portions of a plurality of legs downwardly
extending from the lower end of the retainer 7B are bent to form
connection surfaces 7C connected to the cover 7A. The connection surface
7C is connected to the cover 7A by a low melting point alloy 7D. The low
melting point alloy 7D has a melting point lower than that of the low
melting point alloy 16 in the cylinder 14.

[0099] A protrusion 7E, which can be screwed with the spiral groove 6H of
the support cup 6, is formed on the circumferential surface of the
retainer 7B. The protrusion 7E is formed so that the protrusion 7E
protrudes obliquely downward by making a cut in the circumferential
surface of the retainer 7B. The protrusion 7E has a function of a
stopper, and if trying to pull the retainer 7B out downward when the
retainer 7B is screwed with the spiral groove 6H of the support cup 6,
the protrusion 7E is caught by the spiral groove 6H, so that the retainer
7B is prevented from being pulled out.

[0100] On the other hand, when fitting the retainer 7B into the support
cup 6, the protrusion 7E is elastically deformed on the spiral groove 6H,
so that the protrusion 7E can pass through over the spiral groove 6H.
Therefore, when fitting the retainer 7B into the support cup 6, the
retainer 7B can be fitted by one-push operation to push the retainer 7B
into the support cup 6.

[0101] Next, an assembly procedure and a formation procedure of the
sprinkler head of the first embodiment will be described.

[0102] First, the valve body 3 is fitted into the step portion 2H from the
end of the frame portion 2 of the main body 1. Next, the saddle 20 with
which the compression screw 21 is screwed is put into the frame portion
2.

[0103] Further, the preassembled thermo-sensitive breakup portion 4 in a
state shown in FIG. 4 is inserted into the frame portion 2 so that the
levers 11 are engaged with the positions of the concave portions 20A of
the saddle 20. At this time, the levers 11 are inserted into the frame
portion 2 by causing the levers 11 to pass through the lever insertion
grooves 2D on the inward flanges 2C, and the tips of the levers 11 are
inserted behind the inward flanges 2C. Thereafter, the thermo-sensitive
breakup portion 4 is rotated and the concave portions 20A are engaged
with the levers 11. The thermo-sensitive breakup portion 4 is further
rotated, and the levers 11 are set at positions rotated substantially
90° from the lever insertion grooves 2D.

[0104] Next, a tool such as a wrench or a screwdriver that can rotate the
compression screw 21 is inserted from a through-hole of the set screw 17
of the thermo-sensitive breakup portion 4 and the compression screw 21 is
screwed with the female screw 20B. Then the tip of the compression screw
21 presses the valve body 3, and the tips of the levers 11 press the
inward flanges 2C and elastically deform the inward flanges 2C. The
compression screw 21 is tightened by a predetermined torque, so that it
is possible to control a load by which the valve body 3 presses the water
outlet 1B within a predetermined range. In this way, the assembly
operation is completed by inserting a tool into the through-hole and
screwing the compression screw 21 with the female screw 20B after all the
components such as the valve body 3 are put into the frame portion 2, so
that the assembly operation can be easily performed.

[0105] Next, the deflector 5 is placed in the main body 1. The guide pins
5C are inserted into the holes 5E made in the deflector engaging portions
2G of the main body 1, and then the tips of the guide pins 5C are fixed
to the holes 5B of the deflector 5 by caulking.

[0106] Next, the support cup 6 is placed in the main body 1. In a state in
which the support cup engaging portion 1C of the main body 1 and the
cylindrical portion 6C of the support cup 6 are fitted together, a cut is
made into a plurality of portions of the bottom of the cylindrical
portion 6C. Thereafter, when upper portions of the cuts are pressed in a
direction from the outer circumference of the cylindrical portion 6C to
the constricted portion 1D, the upper portions of the cuts are deformed
along the outer circumferential shape of the constricted portion 1D to
form the engaging portions 6D. The engaging portions 6D and the
constricted portion 1D are engaged together, so that the fixation of the
support cup 6 to the main body 1 is completed. Here, the assembly
procedure of the sprinkler head as a product has been completed.

[0107] The cover plate 7 is connected to the support cup 6 after the
product described above is connected to a pipe and attached to a ceiling
board WC (a state shown in FIG. 7). The cover plate 7 is placed by
screwing the protrusion 7E of the cover plate 7 with the spiral groove 6H
of the support cup 6.

[0108] At this time, the distance between the connection port of the fire
extinguishing system pipe and the ceiling surface may be different for
each connection port of the fire extinguishing system pipe depending on
the design and the construction process. In this case, it is possible to
place the cover plate 7 in accordance with the distance between each
connection port and the ceiling surface by adjusting the insertion length
of the retainer 7B in the support cup 6.

[0109] For example, when the retainer 7B is inserted into the deepest
position of the support cup 6, but the distance between the connection
port of the pipe and the ceiling surface is larger than that shown in
FIG. 1, the insertion length of the retainer 7B may be shortened.

[0110] In this case, in the present embodiment, the deflector engaging
portions 2G are provided at the opening of the frame portion 2 nearest
possible to the ceiling surface, so that the movement range of the
deflector 5 is large. Therefore, even when the insertion length of the
retainer 7B is small and the deflector 5 is placed on the back surface of
the cover plate 7 at a position lower than that shown in FIG. 1, the
installation can be performed without problem. In other words, the
adjustment margin of the installation of a concealed type sprinkler head
A can be large, so that the installation is easy.

[0111] By the above operation, the assembly of the sprinkler head shown in
FIG. 1 is completed.

[0112] Next, the functions and the effects of the sprinkler head A of the
first embodiment will be described.

[0113] The outer circumferential surface protruding to the outside of the
pipe connection portion 1A is formed on the frame portion 2 and the frame
portion 2 includes the beam-like portions 2J (inward flanges 2C) with
which the lever 11 of the thermo-sensitive breakup portion 4 engages and
the openings 2E obtained by cutting off the outer circumferential surface
from the side of the pipe connection portion 1A to the beam-like portion
2J at opposite positions in the outer circumferential surface, so that
the weight of the frame portion 2 can be largely reduced. Therefore, the
load applied to the fire extinguishing system pipe can be reduced, and
the work burden due to the weight load when the sprinkler heads are
conveyed and installed in the fire extinguishing system pipes can also be
reduced.

[0114] The beam-like portions 2J are formed at positions opposite to each
other in the frame 2, so that the press loads of the levers 11 of the
thermo-sensitive breakup portion 4 can be equally applied to both
beam-like portions 2J, and the spring forces caused by deflection of the
beam-like portions 2J can be equally exerted. Therefore, the
thermo-sensitive breakup portion 4 can be continuously and stably
maintained over a number of years. The equal spring forces caused by
deflection of the beam-like portions 2J can explosively eject the
components of the thermo-sensitive breakup portion 4 in the axis
direction of the frame portion 2 when the thermo-sensitive breakup
portion 4 is activated to break up, so that the equal spring forces can
function to prevent the lodgment from occurring.

[0115] The opening end, from which the thermo-sensitive breakup portion 4
is inserted, is formed in the frame portion 2. Therefore, the
thermo-sensitive breakup portion 4 can be inserted from the opening end
of the frame portion 2, so that the thermo-sensitive breakup portion 4
can be easily installed. The thermo-sensitive breakup portion 4 of the
present embodiment is a unit component, so that it is not necessary to
assemble the thermo-sensitive breakup portion 4 while the
thermo-sensitive breakup portion 4 is being installed inside the frame
portion 2. Therefore, the assembly operation can be simplified.

[0116] The openings 2E of the frame portion 2 are provided at a position
near the central axis of the frame 2, which is inner than the outer
circumferential surfaces of the beam-like portions 2J. Thereby, the
openings 2E can be formed at the same time when the cutting operation of
the inner circumferential surfaces of the beam-like portions 2J is
performed. Therefore, it is possible to reduce the manufacturing cost for
forming the openings 2E and providing the beam-like portions 2J without
depending on a dedicated process for forming the openings 2E.

[0117] In the present embodiment, the pipe connection portion 1A and the
frame portion 2 are a forged body having an integrated structure, so that
the number of components can be reduced compared with a case in which
these portions are separate components. Therefore, it is possible to
reduce the cost.

[0118] The lever insertion groove 2D, into which the lever 11 of the
thermo-sensitive breakup portion 4 is inserted, is formed in the inward
flange 2C, so that, when the thermo-sensitive breakup portion 4 is
inserted into the frame portion 2, the lever insertion groove 2D does not
interfere with the thermo-sensitive breakup portion 4. Therefore, the
thermo-sensitive breakup portion 4 can be easily inserted with good
operability.

[0119] In the thermo-sensitive breakup portion 4, the lever 11 is inserted
into the lever insertion groove 2D, and then rotated around the axis of
the frame portion 2, so that the lever 11 is engaged with the inward
flange 2C. Thereby, the assembly operation can be easily performed.

[0120] In the present embodiment, the deflector 5 is provided outside the
opening end of the frame portion 2. Therefore, the deflector 5 can have
various shapes according to the specification and usage of the sprinkler
head to be attached to the sprinkler head, so that different products can
be easily formed. In other words, the product before attaching the
deflector 5 can be commonly used for various products, and products of
different specifications can be easily made by attaching the deflector 5
according to the specification and usage of a desired sprinkler head.

[0121] In the present embodiment, the deflector engaging portion 2G is
provided on the outer circumferential surface of the frame 2 in a
direction outward of the lever insertion groove 2D. Thereby, the position
of the lever 11 of the thermo-sensitive breakup portion 4 is separated
from the deflector engaging portion 2G, so that the lodgment can be
effectively prevented when the thermo-sensitive breakup portion 4 is
activated to break up. In other words, the lever insertion groove 2D is
located on the inner circumferential surface of the frame portion 2 at
which the deflector engaging portion 2G is provided. Thereby, the lever
11 of the thermo-sensitive breakup portion 4 cannot engage at the
position of the inner circumferential surface of the deflector engaging
portion 2G. Therefore, the lever 11 has to engage with the inward flange
2C located away from the deflector engaging portion 2G. Thereby, it is
possible to prevent the lever 11 from hitting the guide pin 5C when the
thermo-sensitive breakup portion 4 is activated to break up and lever 11
flies and drops when the sprinkler head A is activated, so that the
lodgment can be prevented when the thermo-sensitive breakup portion 4 is
activated to break up.

Second Embodiment

FIG. 10

[0122] Next, a second embodiment of the present invention will be
described with reference to FIG. 10.

[0123] A sprinkler head B of the second embodiment shown in FIG. 10 is a
flush type sprinkler head. In the second embodiment, the same components
as those in the first embodiment are denoted by the same reference signs
and detailed description will be omitted.

[0124] The difference between the second embodiment and the first
embodiment will be described. In the second embodiment, the cover plate 7
of the first embodiment is replaced by a ceiling plate 30. In the same
manner as the cover plate 7, the ceiling plate 30 has the retainer 7B
that can be connected to the spiral groove 6H of the support cup 6. The
lower end of the retainer 7B is extended in a flange shape and a plate 31
is formed. The plate 31 has a function to cover over the hole of the
ceiling board WC.

[0125] In FIG. 10, the deflector 5 is exposed from the lower surface
(facing the room) of the ceiling board WC. Surface treatment such as
painting may be performed on the deflector 5 and the plate 31 in
accordance with the color of the ceiling board WC. The guide pin 5C and
the hole 5E of the deflector engaging portion 2F are connected together
by a low melting point alloy 32 in order to place the deflector 5 so that
the deflector 5 does not protrude from the ceiling board WC. The low
melting point alloy 32 has a melting point lower than that of the low
melting point alloy 16 used in the thermo-sensitive breakup portion 4.

[0126] According to the sprinkler head B of the second embodiment, the
same functions and effects as those of the sprinkler head A of the first
embodiment can be obtained. Further, the deflector 5 is normally placed
so as not to protrude from the ceiling board WC, so that the sprinkler
head can be installed without spoiling the beauty of the room.

Third Embodiment

FIG. 11

[0127] Next, a third embodiment of the present invention will be described
with reference to FIG. 11.

[0128] A sprinkler head C of the third embodiment shown in FIG. 11 is a
frame yoke type sprinkler head. In the third embodiment, the same
components as those in the first embodiment are denoted by the same
reference signs and detailed description will be omitted.

[0129] The difference between the third embodiment and the first
embodiment will be described. In the third embodiment, arms 35 and 35 are
connected to the frame portion 2 as deflector engaging portions. The ends
of the arms 35 and 35 are connected together at a position extended from
the water outlet 1B, and a boss portion 36 protruding toward the water
outlet 1B is formed at the connection portion. A plate-shaped deflector
37 is fixed to the opposite side of the boss portion 36. Although not
shown in FIG. 11, the arms 35 and 35 are attached to the frame portion 2
by a method such as screwing, welding, and brazing.

[0130] According to the third embodiment, it is possible to mount the
thermo-sensitive breakup portion 4 in the main body 1, and thereafter
attach the arms 35 to the frame portion 2 and attach the deflector 37 to
the tips of the arms 35. Therefore, many types of products can be made by
attaching the deflectors 37 having a shape in accordance with a desired
specification and usage. If the arms 35 have strength capable of
supporting the water flow discharged from the water outlet 1B by the
deflector 37, the arms 35 can be formed by pins or thin plates. When the
arms 35 are formed by pins or thin plates, the arms 35 can be configured
so as not to interfere with the water flow discharged from the water
outlet 1B.

Modified Examples of the Embodiments

FIG. 12

[0131] Instead of the thermo-sensitive breakup portion 4 of the first to
the third embodiments, it is possible to use a thermo-sensitive breakup
portion including a link in which two thin plates are connected together
by a low melting point alloy and a pair of levers with which the link is
engaged (see Japanese Unexamined Patent Application Publication No.
2008-154697). FIG. 12 shows a modified example of the first embodiment,
which uses such a thermo-sensitive breakup portion 36. The
thermo-sensitive breakup portion 36 can be mounted on the lever engaging
portion 2F of the frame portion 2 while one end of the lever 37 is
engaged with the inward flange 2C (lever engaging portion 2F) and the
other end is engaged with a link 38.

[0132] Although, in the first embodiment, an example is described in which
the components are mounted in the frame portion 2 after the compression
screw 21 is screwed with the female screw 20B of the saddle 20, it is
possible to employ a configuration in which the compression screw 21 is
not screwed with the saddle 20 in advance and the compression screw 21 is
inserted through the through-hole of the set screw 17 of the
thermo-sensitive breakup portion 4 to be engaged with the female screw
20B of the saddle 20 after predetermined components are mounted in the
frame portion 2.

[0133] Although the arms 35 of the third embodiment are illustrated as
components separate from the frame portion 2, a frame portion 2 in which
the arms 35 are integrally formed with a part of the frame portion 2 can
be used.